title: Molecular cloning and characterization of the repetitive DNA sequences that comprise the constitutive heterochromatin of the A and B chromosomes of the Korean field mouse (Apodemus peninsulae, Muridae, Rodentia).
abstract: Three novel families of repetitive DNA sequences were molecularly cloned from the Korean field mouse (Apodemus peninsulae) and characterized by chromosome in-situ hybridization and filter hybridization. They were all localized to the centromeric regions of all autosomes and categorized into major satellite DNA, type I minor, and type II minor repetitive sequences. The type II minor repetitive sequence also hybridized interspersedly in the non-centromeric regions. The major satellite DNA sequence, which consisted of 30 bp elements, was organized in tandem arrays and constituted the majority of centromeric heterochromatin. Three families of repetitive sequences hybridized with B chromosomes in different patterns, suggesting that the B chromosomes of A. peninsulae were derived from A chromosomes and that the three repetitive sequences were amplified independently on each B chromosome. The minor repetitive sequences are present in the genomes of the other seven Apodemus species. In contrast, the major satellite DNA sequences that had a low sequence homology are present only in a few species. These results suggest that the major satellite DNA was amplified with base substitution in A. peninsulae after the divergence of the genus Apodemus from the common ancestor and that the B chromosomes of A. peninsulae might have a species-specific origin.
authors.affiliation: Laboratory of Animal Cytogenetics, Division of Genome Dynamics, Creative Research Initiative Sousei, Hokkaido University, North 10 West 8, Kita-ku, Sapporo, 060-0810, Japan. baramaty@ees.hokudai.ac.jp
authors.forename: Kazumi
authors.initials: K
authors.lastname: Matsubara
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yamada
authors.forename: Shu
authors.initials: S
authors.lastname: Umemoto
authors.forename: Kimiyuki
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Naoki
authors.initials: N
authors.lastname: Ikeda
authors.forename: Chizuko
authors.initials: C
authors.lastname: Nishida
authors.forename: Takahito
authors.initials: T
authors.lastname: Chijiwa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Moriwaki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Matsuda
mesh_terms: D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods*; D033481:Chromosomes, Mammalian / Q000235:genetics*; D003001:Cloning, Molecular; D006570:Heterochromatin / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008969:Molecular Sequence Data; D051189:Murinae / Q000145:classification / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA
chemical_list: D006570:Heterochromatin